The present invention is related to disc drive testing. In particular, the present invention is related to a disc heater for use with a spin-stand.
In a computer disc drive, data is stored on a computer disc in concentric tracks. In many drives, the data is stored using a write head that changes the physical property of the disc. The data is read from the disc by positioning a read head over a desired track and sensing the physical properties of the disc along the track. For example, in a magnetic disc drive, the read head senses magnetic moment boundaries along the disc.
The process for producing a read head or a write head varies depending on the type of read head or write head being produced. Nonetheless, all head manufacturing methods share common characteristics, such as high degree of manufacturing complexity, small feature sizes, and a susceptibility to manufacturing errors. Because of this, each production method generates a significant number of heads that do not meet specifications. In order to detect faulty heads accurately, the transducing heads must be tested over a disc surface. In particular, each transducing head must be flown over a disc surface while it performs writing and/or reading operations. Early in the disc drive manufacturing art, this type of testing was performed after the head was assembled in a complete disc drive. However, this in-drive testing proved to be unacceptable because the disc drive had to be rebuilt if the head was found to be faulty.
To overcome the inefficiencies of in-drive testing, the art developed a xe2x80x9cspin-standxe2x80x9d, which allowed the head to be tested before it was placed in a disc drive. In general, a spin-stand includes a spinning computer disc and a mounting support that supports the head and moves the transducing head to a desired position over the spinning disc. The spin-stand allows a series of tests to be performed on the transducing head including, for example, error-rate testing, pulse width-fifty testing, track average amplitude testing, and track scan testing.
Under normal operating conditions, the internal temperature of a disc drive can reach as high as 75xc2x0 Celsius. This high operating temperature can affect the ability of the transducing head to perform read and write operations. Also, the high temperature can cause a magnetization pattern on the disc to degrade over time. One apparatus used to simulate these worst-case conditions is a test chamber, which can house a plurality of disc drives in a near worst-case environment. One example of such a disc drive test chamber is described in U.S. Pat. No. 5,851,143 to Hamid. Unfortunately, these test chambers provide in-drive testing of disc drives at near worst-case conditions, rather than the generally more desirable outside-drive testing that can be conducted on spin-stand.
There is a need for a spin-stand tester that is capable of simulating near worst-case conditions for analyzing the performance of disc media and transducing heads.
The present invention is directed to a disc heater for use with a spin-stand. The disc heater is adapted to heat a disc that is mounted to a spindle of the spin-stand. The disc heater includes a heater support, a heater, and a controller. The heater support is couplable adjacent the spindle and the disc and is adapted to support the heater near a surface of the disc. The heater produces heat that raises at least a surface of the disc to a temperature that simulates an operating temperature of a disc drive. The controller is electrically coupled to the heater and controls the heat produced by the heater. The spin-stand is adapted to perform various tests on the transducing head. Additional tests, such as accelerated aging studies, can also be performed on the disc.
Another aspect of the present invention is directed to a spin-stand that includes a disc heater